Alex Granovsky
gran@classic.chem.msu.su
I'm sorry for long delay with my reply.
Imposing multiple partially dependent restrictions on a part of a
molecule generally decreases the quality of generated coordinates
and is usually not recommended. You may need to decrease DXMAX
and TRMAX in $statpt to, say, 0.05 or so and increase FMAXT to 100
or so.
Kind regards,
Alex
On Tue Jan 19 '16 6:50pm, GrEv wrote
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>Dear Alex,
>Thanks for your reply.
>Concerning my question, I would use the keyword IFREEZ to completely
>freeze the atoms, however when I do so the geometry optimization stops
>after a few steps with the error that the gradient is beyond the maximum.
>During these few steps the optimization procedure somehow leads to
>increasing the gradient instead of decreasing it. Do you have an idea
>why this happens and how one can cure this.
>Best wishes,
>Evgeniy
>On Sun Jan 17 '16 5:26pm, Alex Granovsky wrote
>----------------------------------------------
>>Dear Evgeniy,
>>no, this is impossible.
>>Kind regards,
>>Alex
>>
>>
>>
>>On Thu Jan 14 '16 7:51pm, GrEv wrote
>>------------------------------------
>>>Dear All,
>>>I would like to freeze atoms completely, avoiding use of the keyword IFREEZ.
>>>There is the keyword IFRZAT, which freezes all the distances between
>>>the specified atoms. However, the atoms frozen with IFRZAT still can rotate as a whole
>>>with respect to the other atoms. I am wondering how one can suppress also
>>>this degree of freedom. (For example, one could freeze the distance from the origin to
>>>the atoms specified in IFRZAT. Is that possible?)
>>>Many thanks!
>>>Evgeniy